1. The Field of the Invention
The present invention generally relates to design and fabrication of structural members. In particular, although not exclusively, the invention relates to roll forming of structural members from light gauge steel in a substantially automated manner from the drafting table to the construction site.
2. The Relevant Technology
A difficulty with conventional building construction is that assembly of the various elements requires skilled labor. The construction process generally involves preparing the structural members on site prior to assembly. In the case of timber, such preparation may involve complex joint shapes to be cut into the timber before joining through the use of machine tools requiring the expertise of a skilled operator. With extruded or roll formed materials, such materials still require joining features to be added subsequent to their production. Assembly also involves general engineering skill such as plan reading to follow the architect""s intended plan. The skilled labor required increases building costs and the degree of skill required means that errors may be made in carrying out the architect""s intended plan.
The design process also requires considerable professional skill including sound engineering knowledge and proficiency with the various codes of practice enforced by the authorities. The professional costs also add considerably to the cost of building.
It will also be appreciated that the transport and delivery of materials to a site adds to the cost of building. Inconvenience and delays will result if materials are not available when required. Preformed, precut and preassembled materials may reduce onsite labor costs but generally need to be well organized so that pieces are not lost or confused.
Another difficulty with conventional building is the huge range of materials required to be transported to a building site. This imposes storage problems as well as the difficulty of coordinating all the required materials to complete a particular job. Any materials on the building site are also liable to theft.
It is therefore an object of the present invention to devise ways of overcoming or at least ameliorating the above-mentioned disadvantages.
In accordance with a first aspect of the present invention, there is provided, a method of fabricating structural members for a building frame according to predetermined specifications of length and connecting features for jointing which enable the structural members to be assembled as a building frame, the method including the steps of: forming the members on a forming machine, the forming machine also creating the connecting features.
The connecting features formed by the forming machine may include holes for fasteners to join the structural members and/or notches shaped to receive intersecting structural members. In a preferred form of the invention, the structural members formed by the forming machine have a web and two arms defining a U-section, with inward strengthening folds at the outer edge of each arm, the connecting features formed by the forming machine including flattened edge portions created by forming back portions of the strengthening folds to at least the plane of the associated arm.
Advantageously, the structural members are formed from steel sheet of approximately 0.55 mm in thickness. However, metal sheet of any thickness may be used. Aluminium alloys may also be used.
In accordance with a second aspect of the present invention there is provided, a method of fabricating a building frame from structural members having respective predetermined specifications of length and connecting features required for jointing, the length and the connecting features being such that the structural members can be assembled to form the frame, the method including the steps of: forming the members to the specifications of length on a forming machine, wherein the forming machine also creating the connecting features; and assembling members to form the frame.
Preferably, the connecting features formed by the forming machine include holes for fasteners to join the structural members and/or notches. Preferably, the structural members formed by the forming machine have a web and two arms defining a U-section, with inward strengthening folds at the outer edge of each arm, the connecting features formed by the forming machine including flattened edge portions created by forming back portions of the strengthening folds to at least the plane of the associated arm.
Desirably, the assembly step is carried out without further substantial modification of the structural members.
The structural members for the frame may be formed with a common section. Preferably, the structural members are formed on the forming machine in an order enabling each member after the first, to be assembled with the previous member(s). Suitably, the structural members are formed consecutively by the forming machine with more than one structural member being formed substantially simultaneously by the forming machine
In a preferred form of the invention, the structural members are formed from steel sheet of approximately 0.55 mm in thickness. However, other metals of other thicknesses are envisaged.
In accordance with a third aspect of the present invention there is provided, a method of designing, by a computer, a building frame having a number of structural members, the method including the steps of: inputting a predetermined plan of the layout and orientation of the structural members in the frame; storing the predetermined plan in a memory means; analysing the stored predetermined plan to provide a specification of length and jointing details for each structural member to enable the structural members made according to specification to fit together to form the frame; and outputting the specifications of each structural member.
Each of the structural members in the plan may be modelled as a basic element and the analysis of the stored predetermined plan may be conducted by converting the basic elements to 3-dimensional section shapes according to the orientation prescribed by the plan. Then, by spatial analysis, section lengths may be calculated, which enable the structural members to fit together. The 3-dimensional section shape may be predefined.
In a preferred form of the method set out above as the third aspect, the method includes inputting a hole locus relative to a section locus, the jointing details for each structural member including holes aligned with holes on an intersecting structural member, the location of each hole being calculated by ascertaining the intersection of the hole locus on one structural member with the hole locus on an intersecting structural member. Preferably, the method is conducted on a forming machine for forming the structural members, and the hole locus is input from feedback provided by the forming machine.
In accordance with a fourth aspect of the present invention there is provided, a method of fabricating a building frame including the following steps: designing, on a computer, the building frame according to the third aspect described above; forming the structural members on a forming machine according to the outputted specifications; and assembling the structural members according to the predetermined plan.
The structural members may be formed with a common section.
The method set out above as the fourth aspect may further include the step of controlling, by computer, the operations of the forming machine, that being the same computer as the computer used for designing the building frame. Advantageously, the structural members are formed on the site where the structural members are assembled. The structural members may be formed by the use of a portable roll forming machine.
In accordance with a fifth aspect of the present invention there is provided, a method of constructing framework for a building, including the steps of: designing the layout of frames defining the building; designing a plan of the layout and orientation of structural members for the frames; analysing the plan to provide a specification of length and jointing details for each structural member to enable the structural members made according to specification to be joined together; creating one or more computer data files of specifications; forming the structural members on a forming machine according to the specifications contained in the computer data file(s); and assembling the formed structural members according to the plan.
Preferably, the structural members have a common section. The method set out above may include the step of controlling, by computer, the operations of the forming machine, that computer also being used for the step of analysing to provide the specifications. In a preferred embodiment of the invention, the structural members are formed on the site where the structural members are assembled. In a most preferred form of the invention, the structural members are formed by the use of a portable roll forming machine.
In accordance with a sixth aspect of the present invention there is provided, a forming machine to fabricate structural members for a building frame, the forming machine including memory means to store structural member specifications of length and connecting features for jointing which enable the structural members to be assembled as a building frame, wherein the forming machine is adapted to form each structural member according to the length specification and create the connecting features according to specification.
Advantageously, the forming machine further includes a computer having: a program with: input means to input a predetermined plan of the layout and orientation of the structural members in the frame; and an analysis engine for deriving the specifications of lengths and jointing details from the predetermined plan. The computer may include the memory means and the computer may be programmed to provide operational control to the forming machine. The forming machine may include rollers to form the structural members from sheet metal.
In accordance with a seventh aspect of the present invention there is provided, a computer program for designing a building frame having a number of structural members including: input means for inputting a predetermined plan of the layout and orientation of each of the structural members in the frame; analysis engine for deriving, from the predetermined plan, a specification of lengths and jointing details to enable structural members made according to specification to fit together to form the frame; and output means for outputting the specifications.
Preferably, each of the structural members in the plan is modelled as a basic element and the analysis engine is programmed to convert the basic elements to 3-dimensional section shapes according to the orientation prescribed by the plan and further, to conduct spatial analysis to calculate section lengths which enable the structural members to fit together.
Parameters of the 3-dimensional section shapes may be provided in the programming. The program may further include parameter input means for user input of the variable parameters of the 3-dimensional section shapes. The analysis engine may programmed to convert the basic elements to a common 3-dimensional section shape.
Advantageously, the program further includes locus input means to input a hole locus relative to a section locus, the jointing details for each structural member including holes aligned with holes on an intersecting structural member, the analysis engine being programmed to calculate the location of each hole by ascertaining the intersection of the hole locus on one structural member with the hole locus on an intersecting structural member.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
The invention consists in the foregoing and also envisages constructions of which the following gives examples.